Workflow Hasenkopf - OSM data to Envi-met

Data Aquisition

The preparation of the modelling environment for an Envimet model run can be as complex as desired, but the following criteria should always be kept in mind 1. the size and desired resolution of the model domain (depending on the research question) 2. scientific or planning level of detail of the research question 4. focus of the modelling (wind field, plant respiration, micrometeorological parameters). The input data must be selected according to these factors. In hilly terrain, a high resolution digital terrain model or digital surface model is essential. In addition, at least a rough estimate of land use and soil type is required. The three-dimensional structure of the model requires at least good estimates of vegetation and building heights in the selected model area.

For the selected question of cold air production in the Hasenkopf area, the freely available data from the State of Hesse and the Hessian Administration for Land Management and Geoinformation, as well as the Openstreetmap data, are well suited. In addition, some planning maps have to be digitised manually.

Download of the data

DEM & DOM

The DEM and DOM files relevant for Marburg can be downloaded from the website of the Hessian Administration for Land Management and Geoinformation

OSM data

Open the downloaded OSM file and search for the following elements (main keys “landuse” and “natural”)

 'allotments'  'farmland'  'farmyard'  'forest'  'grass'   'meadow'  'orchard'  'village_green'  'grassland'  'scrub'  'wood'

Export and project it (EPSG:32632) and name it vegtypes.gpkg.

Then select multistrings (highway key).

primary' 'primary_link' 'residential' 'secondary' 'secondary_link' 'tertiary' 'tertiary_link' 'track

Export and project it (EPSG:32632) and name it surftypes_2.gpkg.

Polygons vegetation

Open the attribute table of vegtypes.gpkg and then the field calculator. Note a new field with 6 alphanumeric characters named ENVIMET_ID. then process the following expressions

CASE 
CASE 
  WHEN "landuse" =   'grass'       THEN '000000'
    WHEN "landuse" =   'meadow'        THEN '000000'
    WHEN "landuse" =   'farmyard'      THEN '0201H4'
    WHEN "landuse" =   'forest'        THEN '0000SM'
    WHEN "landuse" =   'allotments'    THEN '0201H4'
    WHEN "landuse" =   'orchard'       THEN '000051'
  WHEN "natural" =   'grassland'     THEN '000000'  
  WHEN "natural" =   'wood'          THEN '0000SM'
    WHEN "natural" =   'scrub'         THEN '0100H2'  
    ELSE '000000'
END

Save the file.

Polygons surface 1

Open the attribute table of vegtypes.gpkg and the field calculator and edit the following expressions:

CASE 
    WHEN "landuse" =   'farmland'      THEN '02AGSS'
    WHEN "landuse" =   'residental'    THEN '02AGSS'    
    WHEN "landuse" =   'industrial'    THEN '0200AK'
  ELSE '0200AK'

Save the file and name it polygons_surface_1.gpkg.

Line surface types

Buffer the different road types with 8m (primary) 5m (secondary) 4m (tertiary) and 2.5m (tracks).

Then edit the following expression:


CASE 
  WHEN "highway" =   'primary'        THEN '0200AK'
  WHEN "highway" =   'primary_link'   THEN '0200AK'
  WHEN "highway" =   'secondary'      THEN '0200AK'
  WHEN "highway" =   'secondary_link' THEN '0200AK'
  WHEN "highway" =   'tertiary'       THEN '0200AK'
  WHEN "highway" =   'tertiary_link'  THEN '0200AK'  
  WHEN "surface" =   'asphalt'        THEN '0200AK'
    WHEN "surface" =   'ground'         THEN '0200TS'
    WHEN "surface" =   'dirt'           THEN '0200TS'
    WHEN "surface" =   'mud'            THEN '0200TS'
    WHEN "surface" =   'fine_gravel'    THEN '0200BS'
    WHEN "surface" =   'gravel'         THEN '0200BS'
    WHEN "surface" =   'grass'          THEN '02AGSS'
    WHEN "surface" =   'unpaved'        THEN '0200TS'
    WHEN "surface" =   'compacted'      THEN '0200BS'
ELSE '0200TS'
END

Save the file as line_surface_1.gpgk. Now merge polygons_surface_1.gpkg and line_surface_1.gpgk into all_surfaces.gpgk.

Now you can run the Convert Geodata to Envimet plugin.